SUNNYVALE—Chinese search giant Baidu Inc. is often known as the Google of China. Now, it is setting up shop in Google's backyard.

Baidu said Friday it will invest $300 million in a new research-and-development center in Silicon Valley that will have almost 200 employees and be led by Andrew Ng, most recently the head of Stanford University's artificial-intelligence lab. Mr. Ng, who also helped Google Inc. set up its...